Method of making and playing phonograph or sound records



H. OHAGEN Aug. 11, 1931.

Filed April 2. 1928 rammed Aug. 11, 1931 UNITED STA TES- HEINRICHOHAGEN, OF BRESLAU, GERMANY METHOD Oi MAKING AND PLAYING PHONOGRAPH OBSOUND RECORDS Application filed April 2, 1928, Serial No.-266,747, andin Germany April 6, 1927.

The new method has for its object to make inaudible all intraneousnoises which are transmitted onto the diaphragm by the slidmg of thesound-box needle over the sound plate.

p In the commonly used talking-machines intraneous noises are producedby the needle sliding on the sound-plate, which reach the ear in partdirectly and which are in part 19 transmitted by the diaphragm.

'The intraneous noises reaching the ear directly may be made inaudibleby covering the apparatus, but not those transmitted by the diaphragm.

- These intraneous noises are very disturbing at soft tones and at thesoftest piano and also i( luring the intervals in the musicalcomposiion.

The disturbing intraneous noises of the 0 needle dlsappear for thehearing at loud tones of the composition. By the new method alldisturbing intraneous noises of the needle transmitted by the diaphragmare made to disappear even at the soft tones, at the Softm a muslcal comosition.

The disappearing of the intraneous noises cal tones free fromdisturbance and of the needle-noise still existing in the intervals ofthe musical composition, is deadened on the talking-machine by suitabledeadenino measures, and in order to ensure the full final cffeetdeadened at least so far that also the est piano and during theintervals of silence free needle-noise not covered, by any musical tonesand still existing in the intervals in. the musical composition, thesound-strength of which is below the tone strength of the musicalcomposition, becomes inaudible.

Fig. l is a diagram showing the usual relation of the volume of sound ofintraneous noises to the volume of sound of a musical composition. p

Fig. 2 shows this relation according to the present invention. f

At the recording of a musical composition in a tone-strength asdescribed above the engraving stylus oscillates sometimes so much inlateral directions that the sound-grooves merge the one in the other.This inconvenience is obviated by making the spiral-lines engraved bythe stylus at a greater distance the one from the other. Thereproduction of'a musical composition or the like without any disturbingnoises of the sound-box needle is consequently obtained. By furtherdeadening the musical composition, which is now clean, can be brought tothe normal or any desired tone-strength agreeable for the ear.

In the accompanying drawings two diagrams are shown, of which that in rFig. 1 shows the sound strength curves 0 the intraneous noises caused bythe needle of the sound-box' and further the tone strength curve of themusical composition with the 1 intervals in said musical composition.and the deadening curve below which tones or noises are not heardanymore, and how these curves are relatively situated according to thepres ent methods, whilst the diagram shown in Fig. 2 represents themutual position of these three tone or souiid-strengthsanddeadeningeurves according to the new method.

Tn Fig. 1 A A is the curve of the strength of the sound produced by thesound-boxneedle through the intermediary of the diaphragm and a b, c (lc and f, g are the tonestrength curves of the musical composition,

b and 6 f representing the intervals in the musical composition. he isthe deadening curve below which sounds and noises are not audibleanymore.

On the stretch a b, c d, which corresponds to the softest piano or to asoft tone, the tonestrength of the musical composition is below thestrength of the needle-noise and on these stretches as well as on thestretches b 0 and f which represent the intervals in the musicalcomposition, the intraneous noises are disagreeably audible. On thestretches (Z c and f g the tone-strength of the musical composition isabove the sound-strength of the intraneous noises of the needle andthese intraneous noises disappear for the ear.

The deadening curve h i comes in this case When the musical compositionhas been recorded in such tone-strength that at the play ing of thesound-plate the tone-strength of the finest tones of the musicalcomposition is greater than the continually equal soundstrength of theintraneous noises of the needle, the tone-strength-curve a b, c d e f gturbance Fig. 2 a 6, 0d 6, f g, the needlenoise is audible only in theintervals in the musical composition, Fig. 2 Z2 c and e f is deadened inany convenient manner to normal tone-strength or to a tone-strengthagreeable to the ear, at least however to slightly above the sound-curveA A Fig. 2 of the sound-box-needle, the needle-noise becomes alsoinaudible in the intervals of the musical composition, Fig. 2 b 0 e, andf whilst the I sound-strength curves of the needle-noise and thetone-strength curve of the musical com-- position preserve their mutualpositions.

At the clean souncl-eiiect of the musical composition there is no longeraudible any disturbing needle-noise.

I claim I 1. A methodfor eliminating intraneous noises from thereproduction of sounds on talking machines, consisting in the productionof the record at a higher tone volume so that the softest piano of thecomposition rendered is louder than the intraneous noises, and indamping the volume of sound when producing a second record so that theintraneous noises become inaudible.

2. A method for eliminating intraneous noises from the reproduction ofsounds on talking machines, consistin' in the production of the recordat a hi er tone volume so that the softest piano 0 the compositionrendered is louder than the intraneous noises, and in damping the volumeof sound when using the record directly on the record untll an agreeableintensity of sound is obtained and the intraneous noises are inaudible.

In testimonywhereof I afiix my signature.

HEINRICH OHAGEN.

